Problem: Reduce to lowest terms: $ \dfrac{8}{9} \div - \dfrac{1}{8} = {?}$
Solution: Dividing by a fraction is the same as multiplying by the reciprocal of the fraction. The reciprocal of $- \dfrac{1}{8}$ is $- \dfrac{8}{1}$ Therefore: $ \dfrac{8}{9} \div - \dfrac{1}{8} = \dfrac{8}{9} \times - \dfrac{8}{1} $ $ \phantom{ \dfrac{8}{9} \times - \dfrac{8}{1}} = \dfrac{8 \times -8}{9 \times 1} $ $ \phantom{ \dfrac{8}{9} \times - \dfrac{8}{1}} = \dfrac{-64}{9} $